/*
    Copyright 2008 Christian Henning
    Use, modification and distribution are subject to the Boost Software License,
    Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
    http://www.boost.org/LICENSE_1_0.txt).
*/

/*************************************************************************************************/

#ifndef BOOST_GIL_EXTENSION_IO_PNM_SUPPORTED_TYPES_HPP
#define BOOST_GIL_EXTENSION_IO_PNM_SUPPORTED_TYPES_HPP

////////////////////////////////////////////////////////////////////////////////////////
/// \file
/// \brief
/// \author Christian Henning \n
///
/// \date 2008 \n
///
////////////////////////////////////////////////////////////////////////////////////////

#include <boost/mpl/not.hpp>
#include <boost/type_traits/is_same.hpp>

#include <boost/gil/channel.hpp>
#include <boost/gil/color_base.hpp>

namespace boost
{
namespace gil
{
namespace detail
{

// Read Support

template< pnm_image_type::type ASCII_Type
, pnm_image_type::type Binary_Type
>
struct pnm_rw_support_base
{
    static const pnm_image_type::type _asc_type = ASCII_Type;
    static const pnm_image_type::type _bin_type = Binary_Type;
};

template< typename Channel
, typename ColorSpace
>
struct pnm_read_support : read_support_false
            , pnm_rw_support_base< 0
            , 0
            > {};

template< typename BitField, bool Mutable >
struct pnm_read_support< packed_dynamic_channel_reference< BitField
            , 1
            , Mutable
            >
            , gray_t
            > : read_support_true
            , pnm_rw_support_base< pnm_type_mono_asc
            , pnm_type_mono_bin
            > {};

template<>
struct pnm_read_support< bits8
            , gray_t
            > : read_support_true
            , pnm_rw_support_base< pnm_type_gray_asc
            , pnm_type_gray_bin
            > {};


template<>
struct pnm_read_support< bits8
            , rgb_t
            > : read_support_true
            , pnm_rw_support_base< pnm_type_color_asc
            , pnm_type_color_bin
            > {};

// Write support

template< typename Channel
, typename ColorSpace
>
struct pnm_write_support : write_support_false
    {};

template< typename BitField, bool Mutable >
struct pnm_write_support< packed_dynamic_channel_reference< BitField
            , 1
            , Mutable
            >
            , gray_t
            > : write_support_true
            , pnm_rw_support_base< pnm_type_mono_asc
            , pnm_type_mono_bin
            > {};


template<>
struct pnm_write_support< bits8
            , gray_t
            > : write_support_true
            , pnm_rw_support_base< pnm_type_gray_asc
            , pnm_type_gray_bin
            > {};


template<>
struct pnm_write_support< bits8
            , rgb_t
            > : write_support_true
            , pnm_rw_support_base< pnm_type_color_asc
            , pnm_type_color_bin
            > {};

} // namespace detail

template< typename Pixel >
struct is_read_supported< Pixel
            , pnm_tag
            >
            : mpl::bool_< detail::pnm_read_support< typename channel_type< Pixel >::type
            , typename color_space_type< Pixel >::type
            >::is_supported
            >
{
    typedef detail::pnm_read_support< typename channel_type< Pixel >::type
    , typename color_space_type< Pixel >::type
    > parent_t;

    static const pnm_image_type::type _asc_type = parent_t::_asc_type;
    static const pnm_image_type::type _bin_type = parent_t::_bin_type;
};

template< typename Pixel >
struct is_write_supported< Pixel
            , pnm_tag
            >
            : mpl::bool_< detail::pnm_write_support< typename channel_type< Pixel >::type
            , typename color_space_type< Pixel >::type
            >::is_supported
            > {};

} // namespace gil
} // namespace boost


#endif // BOOST_GIL_EXTENSION_IO_PNM_SUPPORTED_TYPES_HPP
